The Best of the BA Festival

Sometimes it can seem like the news is full of scare stories about cancer, but this week has seen two pieces of research that could be seen as good news.

First, six years of research have found that there's no link between mobile phones and brain cancer or brain function, at least in the short term. This adds to a number of other studies that have found no link between mobiles and cancer. Although we still don't know for sure if long-term use of mobiles could have an adverse effect on health, the new study does support the evidence that mobiles are safe.

And at the moment, scientists can't find any explanation as to how radio waves, produced by mobiles and masts, might actually cause cancer - if, indeed, they do at all. The energy of the radio waves is not sufficient to damage DNA. So even if the long-term studies do show an increase in risk, it will be down to a biological mechanism that we don't currently know about.

The other good news story is for women who take the contraceptive pill. Analysis of data from 46,000 women, collected over 36 years by the Royal College of General Practitioners, has shown that taking the pill for less that 8 years doesn't increase your long-term risk of cancer. In fact, the pill may actually cut your risk of certain forms of the disease, such as ovarian, womb and bowel cancer, by between 3 and 12%. That's around one less case of cancer per 2,200 women who have used the pill for a year. But if women took the pill for longer than 8 years, the scientists found a slightly increased risk of cervical cancer, and certain types of brain cancer. On average, the women in the study took the pill for just under 4 years.

It's important to note that this was a long-term study, looking at the risks of cancer many years after women have stopped taking the pill. But while women are actually taking the pill, their risk of breast cancer can be slightly higher. It's also important to remember that the pill is taken by younger women, whose risk of breast cancer is relatively low, so this increased risk is relatively small.

Although exercise is recommended for people who are rehabilitating from a heart attack, new research suggests that you'd probably want to try and steer clear of busy roads while you're doing it.  Scientists at the University of Edinburgh and Umea University in Sweden have measured the effects of diesel exhaust fumes on heart and blood vessel function in twenty men who'd previously had a heart attack.  Each man was put on an exercise bike, and given either clean or polluted air to breathe.  The team found that breathing in the fumes caused changes in the heart's electrical activity. This suggests that air pollution reduces the amount of oxygen that can get to the heart during exercise.  In addition, the researchers found that the body's ability to make a "guardian" protein known as t-PA, which can prevent blood clots from forming, was also reduced by more than a third following exposure to the fumes.

In fact, this explains why previous studies have found that patients with heart disease are more likely to be admitted to hospital on days in which air pollution levels are high. And it also reveals that as well as affecting our lungs, traffic fumes can have a major effect on our hearts too.  The research is particularly relevant for people in areas with lots of diesel-powered traffic.  Diesel engines produce 10 to 100 times more pollutant particles than petrol engines, and the number of diesel-powered automobiles is increasing in Europe and other parts of the world.  Perhaps in the future, we could see the introduction of devices that can filter out harmful particles from exhaust gases.  This might help to improve heart and lung health for us all.

But if you're a heart patient - or know someone who is - then it's probably worth steering clear of busy roads if you're out exercising.  The medical director of the British Heart Foundation, Professor Peter Weissberg, says that "Because of the overwhelming benefits of exercise on heart health, we would still encourage heart patients to exercise regularly, but preferably not when there is a lot of local traffic around.  Heart patients can look out for pollution levels on their local weather forecasts."

Sabine - We've been running an event here, and it's based on a real thing that happened in 1631 when there was an epidemic of plague in York.

Chris - So when you say an epidemic, how big?  How many people were involved?

Sabine - Well, it wasn't in fact one of the worst epidemics which ever affected York, but it was a time when some very draconian measures were introduced to control the plague.  And what the city council, the Aldermen, did at this period was institute a policy of boarding up the infected in their own homes.

Chris - Crikey! What would have happened to those people then?

Sabine - Well, in fact, guards would stand outside their houses and place boards across their doors and windows, and while they would pass the inhabitants of the house some food, they basically waited really until everyone was dead.  It was a way of stopping the plague from spreading.

Chris - But that was quite precient of them, really, to realise you could control a disease like that, wasn't it?

Sabine - Well, certainly by 1631 York had had numerous epidemics of plague and, over the years, of course, people had learned the best way to deal with these sorts of epidemics.

Chris - Which was to confine people?

Sabine - Yes, in fact other policies, such as building pest houses or hospitals would have been very expensive, boarding up people of course was effective and relatively cheap.

Chris - And in an average city like York in the 1600's, if plague came to town, how many people wouldn't come off so well?

Sabine - About a third of the population could be dead by the end of the plague period, so it could be an extremely serious disease.

Chris - James, you're dressed as a priest; so is it your job to bury these poor victims?

James - Amongst other things, yes.  I should explain; My name is Parson Grimsworth, I'm the parson of the parish of St Cuthberts in York, where there's been a severe outbreak of the plague.

Chris - And apart from burying people, what else would you have had to do as the parish parson?

James - I would have gone among them, ministering to them, and preying for the salvation of the city of York.  The plague, I believe, is punishment for the sins of the people of this city.  This is a very rich city full of very idle fellows who spend their time carousing and drinking in the taverns, and gambling down grape lanes...

Chris - And what about in the 17th Century?!

James - In the 17th century it would have been pretty much the same!

Chris - So, stepping out of role for a minute, what do you normally do for a living?

James - I'm working on a project on the history of integrated software in Europe, so it's a bit of a step backwards for me.

Chris - Why do you do this?

James - It comes out of work with the British society for the history of science. All of us involved with this project work with the society as part of it's work in educational outreach.  It's useful to be able to develop these things which appeal to children much more immediately than the kind of static lecture presentation would.

Chris - And Sabine, has it been well received?

Sabine -   Well absolutely, the children we saw this morning were superb, and thy were in role as part of our production; they were city Aldermen and they were able to ask a number of characters, like our parson and also a doctor some questions, and then at the end of our event they had to make the decision about how to control plague in York.

This type of hand drier contains a proximity sensor. If you look underneath the drier, near where the air outlet is, you can see a small glass section, almost like a mini window pane. If you were able to open this up and look inside, you would see an emitter which usually sends out an infra red pulse. Next to the emitter is an infra red receiver. The infra red source is too weak to bounce back from the floor to the receiver, but when you put your hand in the way the infra red beam bounces off your hands back into the receiver and it turns the hot air on. Others are designed with just a receiver to pick up the infra red radiation emitted by your hands.

This may be true, despite that fact that most people think of a virus as being something that makes them feel awful! A recent piece of research in Nature magazine, by US scientist Skip Virgin, suggests that being infected by one of the family of viruses known as Herpes viruses, such as herpes simplex, which causes cold sores, or Epstein-Barr virus, which causes glandular fever can help to boost the function of the immune system. When they infected mice with the rodent equivalents of either of these infections, the mice developed a much better immune response to other pathogens than mice which had never been infected. To prove this, they exposed the mice to the bacteria which causes plague and also listeria; they found these mice to be 100% protected against these bacteria compared with animals which had never been infected with a Herpes virus, which all died. When they studied these mice, they found signalling molecules called interferon gamma were being produced at a much higher level than normal, and this molecule is known to stimulate the immune system.

They think that, because we've been living with members of the herpes viruses for millions of years, the body has come to rely on infection to provide additional gene functions, or immune stimulating factors, which our body no longer has. This programmes a more powerful the immune system, and we get benefit. It's almost a symbiosis, we give the virus a home and it gives us a better immune system...

Meera spoke to John Drury from the University of Sussex about his work on the psychology of crowds...

John -   I gathered data from 145 people, most of whom were actually caught up in the explosions. I was interested in whether their behaviour was selfish and competitive, or cooperative, because there's an assumption that people in emergencies tend to panic. Or if they don't panic, that they simply look after family members.

So first of all, I looked at their behaviour, and I found that selfish and competitive behaviour was extremely rare. On the other hand, mutual help was extremely common. My second question, was who were they with? As you know, most of the people on those trains were commuters. Therefore, most of the people helping each other were with strangers. People were helping strangers. My third question then, was to ask well what was the process behind this helping of strangers? They contrasted this with the experience you have everyday on the underground, where people feel atomised, and so it was this sense of unity, arising from the danger itself that brought people together that explains there helping behaviour.

Meera -   What were your overall conclusions from this?

John -   First of all, that the idea of panic is a myth. Secondly, that the authorities should make provisions for peoples willingness to provide help for each other (the public tend to be excluded from emergencies), and thirdly, the authorities, rather than treating people as irrational and overemotional, should try to give more information to the public on what's happening during emergencies.

Meera - You say communication should be improved. Why should communication be improved and how can it be improved?

John -   Well there is evidence, not just from my study but from other experimental studies, that when you give people more information about the nature of the danger, the location of the danger, people exit more effectively. The assumption is, that the more information you give people, the more they panic. Well that's not actually true. So you should have tannoy systems in place, that tell people the location and the nature of the danger so they can upon it.

Meera - Do you think we should all promote actually having contact with each other in normal circumstances?

John -   There is some lesson about everyday life here as well. Because, when you go on the tube, some of my people did draw a contrast between how people avoid each other's eyes, and I think the authorities and those in control of public spaces can do something about this by addressing people increasingly by their collective identity and in that way they can encourage more helping and cooperative and altruistic behaviour that we get in everyday life at the moment.

 - Music -

Meera -   So that, was music played purely by the use of sensors. I'm here with David who's going to explain to me how that's possible. Hello David!

David - Hello, yes I've been working with some children from the Applefield special needs school in York and the idea of the project is that it gives access to children who wouldn't normally have access to keyboards and so on for the reason of their disabilities and allows them to play music on the computer. The computer is a kind of software sampler and they control the playback with sensors. Now, these are things like infra-red distance sensors, the sort of thing that when you go to the supermarket the doors open automatically-there's something there that detects your movement. So we've got distance sensors, sensors you can tilt and move around and also pressure sensors.

Meera - There was something that resembled a cymbal but the children just kept there hand hovering over it, so that was a distance sensor?

David -   Yes that's a distance sensor. It sends out a little infra-red beam and then movement in front of it bounces back, the sensor detects the distance and then there's software inside the computer that translates that into control information for the sample playback. They can control the part of the sound that's playing back and also the pitch of the sound.

Meera -   Well, that was a very impressive result, so I hope the children are happy?

David -   There are some definite future stars among them I think....

Meera -   I've just arrived on Parliament Street and glaring me in the face is a huge, multi-coloured, multi-pathed inflated dome!So, I've just come inside the dome and it's really quite surreal. There's paths going in a quite a few directions and the colours are just really vibrant. All the paths are lined with bright blue and bright red. I'm here with Paul, who's going to explain how they get this effect. Hi Paul,

Paul -   Hello. You said it's very bright in here, in fact it is relatively dark in here compared to outside. The only light in here is from sunlight that comes through the plastic and is filtered into the structure, and red, green and blue are used specifically because they're the primary colours of light. So they're the colour we pick up in our eyes, all the other colours you see by the way are combinations of the three. While its relatively dark in here, you're more or less getting 100% of the red, blue and green from the sun separated from those three and tour eyes are, at the same time, dilated in order to receive more light because you're aware that it's actually fairly dark in here. So you're eyes are adjusted to get as much light as possible and you're still getting, independently, 100% of the three primaries which is what gives it that effect of being very bright and vibrant.

Meera -  I've just managed to bump into Helen. Hello Helen.

Helen -  Hello.

Meera -  This is all part of the BA Festival of science, did you know that was going on?

Helen -  I actually didn't know, no. I just came into town and found all these interesting things going on in town! And it's good for something to be different as well, because normally its fruit and veg ...flowers...food...and to see something to do with science is really interesting.

Meera - Well that's it from me, I hope you've enjoyed listening to the best of the fest!